Toby Manhire: Population growth? Open the doors and let 'em in

It's just a number, and a very ball-park number at that, but it makes for a good story. Yesterday, the people at Statistics New Zealand tell us, the population reached 4,444,444.

"And who knows?" enthused the statistics population manager, scrambling to fill the space in the press release, "that new boy or girl might even be born at 4.44 in the morning."

And maybe the baby was delivered in the back seat of a 4x4. Who knows!

Still, it scored a few headlines, and that's worth something. Because we don't hear a lot about the size of New Zealand's population, except when it comes to one of us prattling on about punching above weight, or a clever visitor remarking, probably wrongly, on the ratio of people to sheep. Or when it relates to the fact that we're ageing as a nation.

In part to counteract that boomer-to-Zimmer bulge, we should be thinking seriously about an ambitious population boost. We have the 30th biggest population of the 34 in the OECD club of rich countries. We're 29th when it comes to population density.

Who honestly can say they feel crowded anywhere in New Zealand? Apart from in city traffic, this place is an agoraphobe's worst nightmare.

The "tyranny of distance" has become a New Zealand cliche. But as technology in transport and communication shrink that distance, the greater tyranny becomes scale. We're only little. And, sure, we don't want to be enormous, but there's good evidence that a bit bigger can be a lot better.

In a working paper published at the start of the year, the NZ Institute of Economic Research directly tackled the question of New Zealand's population size. The authors make the case for a bold push to increase the population, pointing to gains to be made in a range of areas - the boons of what the demographers call "agglomeration".

These include an enhanced physical and institutional infrastructure, more internal market competition (the report's authors emphasise invigorating cities other than Auckland), greater specialisation, a wider range of employment options, and a tendency to higher wages.

More people means more bums on seats - enriching and expanding the arts, sport and media. It is not through self-interest, for example, that Neil Finn says a population of 10 million or more would do wonders for New Zealand music.

The NZIER report, which we will forgive its title, "Grow for it", argues for an annual increase of 2.5 per cent, which would tally up to 15 million by 2060. Two-and-a-half per cent may not look huge, but it would match the sustained population rise of the post-war boomer years, and is cumulatively huge.

Increased fertility might help, but it could realistically be realised only through immigration. It wouldn't mean loosening turnstiles, rather than opening floodgates, by tweaking rules to encourage more arrivals. A mix, say, of skilled workers, family members, and refugees. Foreign students who complete degrees in New Zealand could get the nod. A green card lottery, maybe. And flamboyant German internet entrepreneurs, obviously.

A plan to boost the population would necessarily require an equally bold and cohesive programme to ensure preservation of the environment, energy sources, social services, transport, and so on. There would be implications for tangata whenua. And it would demand housing solutions on an altogether different level from those announced this week, which are likely to have roughly the effect of paddling a waka with a toothpick. Perhaps most challengingly of all, it would require most of us to accept that the quarter-acre pavlova paradise is a fond, largely imaginary, national memory.

And not without reason, many regard broaching the immigration debate as something like kissing a cactus. It can create a head-spinning swirl in which it's difficult to discern the dog-whistling sophistry from the legitimate cultural anxiety.

So none of this is possible without a national population policy, without a bold and ambitious medium to long-term vision - something to which the politicians of today seem fashionably allergic. The best solution -call me a fantasist - would be a cross-party working group to address the subject. And that sort of effort, that sort of vision might just dissuade New Zealanders from upping sticks. It might even spur some of those abroad to think about coming back.

The latest official estimates suggest we won't get to 5,555,555 for another 30 years. Too slow. How about this? Increase the population of our nation of migrants and mariners by 2.5 per cent a year for 33 years, and in 2045 we should hit 9,999,999. Maybe, who knows, on the ninth of September.